Process for flameproofing cellulose-containing fibre material

ABSTRACT

A process for the flame-proofing of cellulose-containing fibrous materials by applying to the substrates aqueous preparations containing a self-condensation product of an N-methylolamide of a dialkyl, dihalogenalkyl or dialkenyl phosphonopropionic acid advantageously together with a curable aminoplast precondensate.

States Patent 1 Nachbur et a1.

[ PROCESS FOR FLAMEPROOFING CELLULOSE-CONTAINING FIBRE MATERIAL [73]Assignee: Ciba-Geigy AG, Basel, Switzerland [22] Filed: June 9, 1971[21] App1.No.: 151,529

[30] Foreign Application Priority Data June 11, 1970 Switzerland 8807/70[52] 11.8. CI 117/136, 117/143 A, 117/145, 250/8.1 [51] Int. Cl. C09k3/28, D06m 13/32 [58] Field of Search 117/136,143 A, 145; 252/8.l

[5 6] References Cited UNITED STATES PATENTS 3,577,270 5/1971 Guth et al117/136 strates [451 Aug. 28, 1973 Primary Examiner-William D. MartinAssistant Examiner-Harry J. Gwinnell Attorney1-1arry Goldsmith, JosephG. Kolodny and Mario A. Monaco [5 7] ABSTRACT A process for theflame-proofing of cellulosecontaining fibrous materials by applying tothe subaqueous preparations containing a selfcondensation product of anN-methylolamide of a dial- I kyl, dihalogenalkyl or dialkenylphosphonopropionic acid advantageously together with a curableaminoplast precondensate.

9 Claims, No Drawings PROCESS FOR FLAMEPROOFING CELLULOSE-CONTAININGFIBRE MATERIAL The subject of the invention is a process forflameproofing cellulose-containing fibre material, character ised inthat this material is treated with an aqueous preparation which containsat least one reaction product which is obtained if an anhydrousN-methylolamide of the formula R1O O wherein R, and R each denote analkyl, halogenoalkyl or alkenyl radical with one to four carbon atoms,is condensed with itself in an anhydrous medium, optionally using anacid catalyst, in the presence of an inert organic solvent, at 70 to 180C, the condensation being continued until about 0.7 to 1 mol of waterhas separated per 1 mol of N-methylol-amide employed, and optionallycontains a curable aminoplast precondensate, and the material isthereafter dried and subjected to a treatment at elevated temperature.

In the formula l the radicals R, and R can thus be identical, ordifferent from one another. As a rule, R, and R denote two identicalradicals of the indicated composition. Chloroalkyl groups, such as 2-chloroethyl, or 2,3-dichlorophenyl groups, but preferably n-propyl,isopropyl, ethyl, methyl or allyl groups, may be mentioned as examples.

In the manufacture of the reaction products, N- methylolamides of theformula wherein R, has the indicated meaning, are accordingly usedpreferentially.

Particularly suitable reaction products are those which are manufacturedfrom N-methylolamides of the formula Ra-O wherein R, denotes an ethyl ormethyl radical, or above all of the formula minutes, appropriately 25 to30 minutes. If desired, methylolation can also be carried out in thepresence of an inert solvent or suspending agent such as, for example,toluene, but preferably the reaction is carried out without solvents.

In the self-condensation of the N-methylolamides thus obtained, methodswhich are in themselves known are again used. An appropriate procedureis to condense at least one N-methylolamide of the formula l which mustbe in an anhydrous form, with itself, in an anhydrous medium, optionallyusing an acid catalyst, in the presence of an organic solvent, bywarming up to the boiling point of the solvent in question. The reactionis continued until about 0.7 to 1, preferably about 0.9 to l, orespecially about 1, mol of water has separated in the water separatorper 1 mol of N- methylolamide employed. Suitable organic solvents forthe reaction are, for example, toluene, benzene or xylene. Thecondensation temperature is preferably to C. After completion of thereaction, at most 25 percent of the formaldehyde bonded as methylolgroups in the starting product are still detectable in the reactionproduct, again as bonded formaldehyde. Practically the original amountof formaldehyde bonded as CI-I OI-I can be recovered by boiling in wateror by splitting with phosphoric acid.

The reaction products to be used according to the invention are mixturesof self-condensation products of the compound of the formula (1) whichas a rule contain not more than I5 structural elements of a compound ofthe formula l per molecule, and the individual polycondensed productscan have a linear, branched or unbranched structure, or a cyclicstructure. Because of the great complexity of the reaction productmixtures it is however not possible to determine the composition of thereaction products, or selfcondensation products, to be used according tothe invention accurately by means of the customary methods ofinvestigation.

The pH value of the aqueous preparations containing the reactionproducts and which are to be used according to the invention forflameproofing cellulosecontaining material, is advantageously less thanfive, and in particular less than three. In order to achieve this,strong mineral acids, such as sulphuric acid, nitric acid, hydrochloricacid or preferably orthophosphoric acid, are added to the preparation.Instead of the acids themselves, especially hydrochloric acid, it isalso possible to use compounds from which the corresponding acids areeasily, for example even without warming, formed in water by hydrolysis.As examples, phosphorus trichloride, phosphorus pentachloride,phosphorus oxychloride, thionyl chloride, sulphuryl chloride, cyanicchloride, acetyl chloride and chloroacetyl chloride may here bementioned. These compounds on hydrolysis yield exclusively aciddecomposition products, for example cyanuric acid and hydrochloric acid.Instead of using one of the strong acids, it can be advantageous to usethe acid mixtures that correspond to the hydrolysis products of one ofthe compounds of which mention has just been made, that is to say, forexample, instead of hydrochloric acid alone, to use a mixturecorresponding to the phosphorus pentachloride of hydrochloric acid andortho-phosphoric acid corresponding to the phosphorus pentachloride,appropriately in the molecular ratio 1:5.

The conjoint use of these acid catalysts may well be advantageous, butis not absolutely essential for achieving good flameproofing effects.

The preparations for flameproofing can also contain a latent acidcatalyst for accelerating the curing of the aminoplast precondensatewhich may be present and for cross-linking the reaction products. Latentacid catalysts which can be used are the catalysts known for curingaminoplasts on cellulose-containing material, for example ammoniumdihydrogen orthophosphate, magnesium chloride, zinc nitrate and aboveall ammonium chloride.

Apart from the reaction products and the additives required to adjustthe pH value, and the curing catalysts, the preparations to be usedaccording to the invention can contain yet further substances. Anaddition of aminoplast precondensates can be advantageous for achievinga good wash-resistant flameproof finish, but is not essential.

By aminoplast precondensates there are understood addition products offormaldehyde to nitrogen compounds which can be methylolated. 1,3,5-aminotriazines, such as N-substituted melamines, for exampleN-butylmelamine, N- trihalogenomethylmelamines, as well as ammeline,guanamines, for example benzoguanamines, acetoguanamine or diguanamines,may be mentioned. Further possibilities are: alkylureas or arylureas andalkylthioureas or arylthioureas, alkylene-ureas or alkylenediureas, forexample ethyleneurea, propyleneurea, acetylenediurea or especially4,5-dihydroxyirnidazolidone-2 and derivatives thereof, for example4,5-dihydroxyimidazolidone-2 substituted by the radical CH CI-ICONI-I-CH OH at the hydroxyl group in the 4-position. The methylolcompounds of a urea, of an ethyleneurea or of melamine arepreferentially used. Products which are as highly methylolated aspossible in general yield particularly valuable products. Suitableaminoplast precondensates are both predominantly monomolecularaminoplasts and also more highly precondensed aminoplasts.

The ethers of these aminoplast precondensates can also be used togetherwith the reaction products. The ethers of alkanols such as methanol,ethanol, npropanol, isopropanol, n-butanol or pentanols are, forexample, advantageous. It is however desirable that these aminoplastprecondensates should be watersoluble, such as, for example,pentamethylolmelaminedimethyl-ether.

It can also be advantageous if the preparations contain a copolymer,obtainable by polymerisation in aqueous emulsion, of (a) 0.25 to percentof an alkaline earth salt of an afi'ethylenically unsaturatedmonocarboxylic acid, (b) 0.25 to 30 percent of a N- methylolamide orN-methylolamide-ether of an a,B-ethylenically unsaturated monocarboxylicor dicarboxylic acid, and (c) 99.5 to 60 percent of at least one othercopolymerisable compound. These copolymers, and their manufacture, arealso known. The tear strength and abrasion resistance of the treatedfibre material can be advantageously influenced by the conjoint use ofsuch a copolymer.

A further additive to be mentioned which is advantageous in some casesis a softening dressing, for example an aqueous polyethylene emulsion orethylene copolymer emulsion.

The preparations can furthermore also contain solubilising agents, suchas organic solvents which are miscible with water, for example ethanolor methanol.

The content of reaction product in the aqueous preparations isappropriately so chosen that 15 to 40 percent is applied to the materialto be treated. Here it is necessary to take into account that thecommercially available textile materials of native or regeneratedcellulose can absorb between 50 and percent of an aqueous preparation.As a rule, the aqueous preparations contain 200 to 700 g/l preferably300 to 500 g/l, of the reaction product.

The amount of the additive which is required to adjust the hydrogen ionconcentration to a value of less than five depends on the selected valueitself and on the nature of the additive, but must in all circumstancesbe not less than a certain minimum. A certain excess over this minimumamount is in general to be recommended. Large excesses do not offer anyadvantages and can even prove harmful.

If additionally a polymer of the type indicated is added to thepreparation, then this is advantageously done in small amounts, forexample 1 to 10 percent, relative to the amount of the reaction product.The same is true of a plasticiser which may be added, where theappropriate amounts can again be 1 to 10 percent.

The preparations are now applied to the cellulosecontaining fibrematerials, especially textiles, for example linen, cotton, rayon, stapleviscose or fibre mixtures of such materials with others, such as wool,polyamide or polyester fibres, and this application can be effected in amanner which is in itself known. Preferably, piece goods are used andare impregnated on a padder of the customary construction, which is fedwith the preparation at room temperature.

The fibre material thus impregnated must now be dried, which isappropriately done at temperatures of up to 100C. Thereafter it issubjected to a dry heat treatment at temperatures above 100C, forexample between and 200C, and preferably between and C. Generallyspeaking, the higher the temperature, the shorter the duration of thetreatment. This heat treatment lasts, for example, from 2 to 6 minutesat temperatures of 140 to 170C.

A rinse with an acid-binding agent, preferably with aqueous sodiumcarbonate solution, for example at between 40C and the boil, and for 3to 10 minutes, is advisable in the case of a strongly acid reactionmedium.

As already indicated, the present process is capable of yieldingflameproof finishes which are largely preserved even after repeatedwashing or dry cleaning, and which do not cause any unacceptabledeterioration of the textile-mechanical properties of the treatedmaterial.

In the manufacturing instruction and example which follow, parts andpercentages are parts by weight and percentages by weight. Therelationship of parts by volume to parts by weight is as of ml to g.

MANUFACTURING INSTRUCTION I 181 parts (1 mol) of 3-(dimethylphosphono)-propionic acid amide, 30.75 parts of 97.8 percent strengthparaformaldehyde and one part of NaOCI-I (powder) are reacted in astirred flask of 500 parts by volume capacity, equipped with a refluxcondenser and thermometer, for 30 minutes at 100C internal temperature.Thereafter, the mixture is cooled and the resultflask and condensed atthe reflux temperature of the: 1

toluene. After 3 hours, the reaction is complete and 18 parts (1 mol) ofwater have been obtained. The mixture is cooled to 60C and diluted with160 parts of methanol, and the resulting solution is freed of traces ofimpurities by filtration. Thereafter the toluene-methanol mixture isremoved in vacuo at 60C. A colourless, thick syrupy product is obtained,which still contains 2.4 parts of total formaldehyde. A sample of 2.5parts of the reaction product is dissolved in 40 parts of water andheated to 100C for 30 minutes. 22 parts of total formaldehyde(calculated relative to the total reaction product) are found.

MANUFACTURING INSTRUCTION II 264 parts of an 80 percent strength aqueoussolution of 3-(dimethylphosphono)-propionic acid N- methylolamide, 1part of p-toluenesulphonic acidv monohydrate and 200 parts of benzeneare brought to the boil, with rapid stirring, in a stirred flask of 500parts by volume capacity which is provided with "a water separator andthermometer. 61.5 parts of water are separated off azeotropically overthe course of about 3% hours. The benzene is thereafter replaced bytoluene and the self-condensation is completed at the boiling point ofthe toluene. A total of 69 parts of water are thus obtained, and afterdeduction of the water contained in the starting product this amounts to18 parts of water formed during the condensation. Thereafter, thetoluene is largely removed, the reaction product is dissolved in 80parts of methanol and the solution filtered, and the methanol andresidual amount of toluene are then distilled off in vacuo at about 50C.

166 parts of an opalescent, syrupy product are obtained, which stillcontains 3.8 parts of total formaldehyde. Of these, 2.3 parts arepresent as free formaldehyde.

MANUFACTURING INSTRUCTION III 284 parts of an 80 percent strengthaqueous solution of 3-(diethyl-phosphono)-propionic acid N-methylolamide in 200 parts of toluene and 1 part of p-toluenesulphonicacid monohydrate are condensed, at the boiling point of the toluene, ina stirred flask of 500 parts by volume capacity, equipped with a waterseparator and thermometer. Altogether, 68 parts of water are obtained,which after deduction of the water contained in the starting productamounts to 11 parts of water formed during the condensation. Afterworking up in accordance with manufacturing instruction II, 217 parts ofreaction product are obtained.

MANUFACTURING INSTRUCTION IV 192.8 parts (0.83 mol) ofdiallylphosphonopropionic acid amide, 25.6 parts of 98 percent strengthparaformaldehyde (0.83 mol) and 0.8 part of pulverulent sodium methoxideare treated for 30 minutes at 100C internal temperature in a stirredflask of 500 parts by volume capacity, which is equipped with a waterseparator and thermometer. A melt of diallylphosphono- ,propionic acidN-methylolamide is obtained. Thereafter 200 parts of toluene and 0.8part of p-toluenesulphonic acid are added and the self-condensation iscarried out at the boiling point of the .toluene. 1 1 parts of water areobtained. The highly viscous reaction product is finally diluted toabout 65 percent solids content with water, for greater ease ofmanipulation.

EXAMPLE 1 A cotton fabric or a viscose rayon fabric is padded with oneof the aqueous liquors A to D of Table 1 below. The liquor uptake is 80and 86 percent respectively. The fabric is dried at to C and the productthereafter cured for 4% minutes at 160C. A part of the fabric is nowfurther washed for 5 minutes in a solution containing 2 g of anhydroussodium carbonate per litre of water, at the boil (cotton) or at 60C(viscose rayon), and is rinsed and dried. A further part of this fabricis now boiled ten times for 30 minutes, or washed ten times for 30minutes at 60C, in a solution which contains 2 g of anhydrous sodiumcarbonate and 5 g of soap per litre of water 10 SNV-4 or SNV-3 washes).

The individual pieces of fabric are then tested for their flameresistance (vertical test according to DIN 53,906). The results of thistest are also summarised in Table I below.

TABLE I Treated with preparation Constituents I Untreated A B 0 Productaccording to manulac- 500 500 450 turing instruction I, g./l.Pentamethylolmelamine- 8O dimethyl-ether (60%), g./1. H3PO4 g/l pH valueof the preparation 2. 7

EXAMPLE 2 A cotton fabric or a viscose rayon fabric is padded with oneof the aqueous liquors E to K of Table ll below. The liquor uptake is 80percent. The fabric is dried at 70 to 80C and the product thereaftercured for 5 minutes at C.

A part of the fabric is now re-washed for 5 minutes in a liquor whichcontains 4 gof anhydrous sodium carbonate per litre, at the boil(cotton) or at 60C (viscose rayon), rinsed and dried. A further part ofthe fabric, for determining the degree of fixing, is not re-washed.

A further part of the cotton fabric is washed 5, l0 and 20 times for 45minutes at the boil in a household washing machine. The wash liquorcontains 5 g of a full strength detergent per litre (SNV 198,861).

The individual pieces of fabric are then tested for their flameresistance (vertical test according to DIN- 53,906, ignition time 6seconds).

The results of this test and the determinations of the degree of fixingare summarised in Table 11 below. S.C. denotes solids content P.C.denotes phosphorus content.

TABLE II Treated with preparation Constituents S.C. 1*.(1. Untreated E FG H J K Product according to manufacturinginstruction, g., l.: N

V Pentamcthylolmclnniine-(limethylcihcr (0 IlgPOJSflLg/l l, g./l r rFlame resistance:

Cotton fabric:

Alter rcavushing:

Burning time (seconds) Burns 0 n 0 0 0 Tour length (cm) 11. 5 11.5 After5 washes (SNV 193,861):

Burning time (seconds) 11 U 0 U Tear length (cm.)& 11 12.5 11 11 1 After10 Washes:

Burning time (seconds) Burns..... 0 (l 0 o u (1 Tour length (0111.) 1312.5 12 12 u 13 After washes:

Burning time (seconds) Burns 0 (I O n Tear length (cn1.) N 10 0.5 11.510 12 Viscose rayon fabric:

After rc-wnshing B\1rns 0 (J Burning time (seconds) Burns l) u Tearlength (cm.) 11.5 10.5 Determination of degree of fixing, deposit inpercent (rclaiire t0 fibre weight):

Cotton fabric:

(a) not reqvashed 22.8 20.1 34.1 348.2 27 24.1 (b) re-washed 11 12 1013.5 12.4 13.1 Degree of fixing (percent) (relative to deposit) 48 G1)29 45 46 54 Viscose rayon:

(a) not re-washed. 22.4 20.2 33 5 27.5 26.1 23.1 (b) re-washed 10,3 12 35 8.5 9.2 11.6 Degree of fixing (percent) (relative to depos 4G 59 10 531 35 50 We claim 6. Process according to claim 1, wherein thereaction 1. Process for flameproofing cclluloscmontaining product is aself-condensation product of a N- fibre material, which comprisestreating this material methylolamide' of the formula with an aqueouspreparation containing at least one reaction product which is obtainedby sclf-condensation (1) Ri-o o in an anhydrous medium of an anhydrousN- meth l l i y 0 am do of the formula Bro CHFCHrC iwherein R and R arethe same.

P 7. Process according to claim 1, wherein the reaction \OHPCHPC productis a self-condensation product of a N- methylolamidc of the formula 40wherein R and R each denote an alkyl, halogenoalkyl O or alkenyl radicalwith one to four carbon atoms, in the presence of an inert organicsolvent, at 70 to 180C,

the condensation being continued until about 0.7 to 1 Bro CHFCHPC O NHCH OH mol of water has separated per 1 mol of N- methylolamidc employed,drying the treated material and subjecting the dried material to anelevated tempcraturc.

2. Process according to claim 1, wherein the reaction product is aself-condensation product obtained in the presence of an acid catalyst.

wherein R and R are the same and are ethyl or methyl radicals.

8. Process according to claim 1, wherein the reaction product is aself-condensation product of the N- mcthylolamidc of the formula 3.Process according to claim 1, wherein the aqueous R -O 0 preparationcontains additionally a curable aminoplast precondensate R3'o om-cHr-cO-NH-CH -OH 4. Process according to claim 1, wherein the elevatedtemperature is between 130 and 200C.

5. Process according to claim 1, wherein the reaction product is a scltcondcnsation product obtained by separating 0.9 to 1 mol of water per 1mol of N- methylolamide.

9. Process according to claim 1, wherein the reaction product isobtained by carrying out the condensation reaction at temperatures fromto C.

.. ....|..I rbac Case 1-7073/E NT OFF UNITED STATFS PATF. CERTIFICATE01* CORRECTION Dated Patent No.

August 28, 1973 HERMANN NACHBUR ET AL Inventor(s) It is certifiedthaterror appears in theabove-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 8, claim 8, lines 52 and 5%, change "R to Signed and sealed this18th day of December 1973.

(SEAL) Attest:

RENE D TEGTMEYER Acting Commissioner of Patents H mm? 6 C c 7 Ti Wwf i Dt R 5 A6 wt t E A Case 1-7073/E UNITED STATES PATENT OFFICE CER'IIFICATEOF CORRECTION Patent No. 3,75 59 Dated' August 973 ln n fl HERMANNNACHBUR ET AL It is certified that error appears in the above-identifiedpatent and that said Letters Patent are hereby corrected as shown below:

Column 8, claim 8, lines 52 and 54, change "R to H C-F 3 V Signed andsealed this 18th day of December 1973.

(SEAL) Attest:

RENE D. TEGTMEYER Acting Commissioner of Patents EDWARD M. FLETCHER, JR.Attesting Officer

2. Process according to claim 1, wherein the reaction product is aself-condensation product obtained in the presence of an acid catalyst.3. Process according to claim 1, wherein the aqueous preparationcontains additionally a curable aminoplast precondensate.
 4. Processaccording to claim 1, wherein the elevated temperature is between 130*and 200*C.
 5. Process according to claim 1, wherein the reaction productis a self-condensation product obtained by separating 0.9 to 1 mol ofwater per 1 mol of N-methylolamide.
 6. Process according to claim 1,wherein the reaction product is a self-condensation product of aN-methylolamide of the formula
 7. Process according to claim 1, whereinthe reaction product is a self-condensation product of a N-methylolamideof the formula
 8. Process according to claim 1, wherein the reactionproduct is a self-condensation product of the N-methylolamide of theformula
 9. Process according to claim 1, wherein the reaction product isobtained by carrying out the condensation reaction at temperatures from80* to 140*C.